Apparatus for producing mechanical oscillations suitable for controlling sweep circuits and other devices



y 4, 1967 n. s. BLONDER 3,329,909

APPARATUS FOR PRODUCING MECHANICAL OSCILLATIONS SUITABLE FOR CONTROLLING SWEEP CIRCUITS AND OTHER DEVICES Original Filed Dec. 27, 1962 FIG-l OSCILLATOR CIRCUIT FIG.2

INVENTOR ISAAC S. BLONDER ATTORNEYS United States Patent 3,329,909 APPARATUS FOR PRODUCING MECHANICAL OSCILLATIONS SUITABLE F O R CONTROL- LING SWEEP CIRCUITS AND OTHER DEVICES Isaac S. Blonder, West Orange, NJ.

(9 Alling St., Newark, NJ. 07102) Continuation of application Ser. No. 247,568, Dec. 27, 1962. This application Feb. 21, 1966, Ser. No. 534,944 6 Claims. (Cl. 331178) This application is a continuation of Ser. No. 247,568, filed Dec. 27, 1962, and now abandoned, for Method of and Apparatus for Producing Mechanical Oscillations Suitable for Controlling Sweep Circuits and Others Devices.

The present invention relates to apparatus for producing mechanical oscillations, and, more particularly, to vibratory systems adapted to control a wide range of devices, such as electrical frequency sweep circuits, mechanical loads, and other devices.

The art is replete with oscillatory or vibratory devices for producing a reciprocating motion that may be used for driving mechanical loads, including variable electrical or electronic elements for such purposes as effecting repetitively varying electrical effects. Vibratory, reciprocating or back-and-forth linear or angular motions, all hereinafter generically referred to as oscillatory movement, may, of course, be employed for a host of purposes ranging from the functions of mechanical stirrers or vibrators to, for example, the control of electrical tuning elements for producing frequency sweeping. Such oscillatory movement has previously been produced by vibrating reed-like members, rotatable members driving r-otary-to-linear eccentric or cam-controlled linkages, and reversible motor devices and the like.

The complexity of reed-like driving systems and their inherent restrictions in range of adjustment and oscillatory amplitude or limit control have been serious deterrents to wide-scale general use of such devices for the above-described purposes. The vary nature of off-center eccentric linkages for converting rotary movement into oscillatory movement introduces serious wear and life problems as a result of the inherent thrusts on bearings. In addition, it is difficult to render linkages adjustable to control the limits of oscillatory movement and the center or rest position thereof. Reversible motor systems also are subject to restrictions in the range of possible frequency of oscillatory movement and in adjustability and are expensive and complicated, as well.

An object of the present invention, accordingly, is to provide a new and improved apparatus for producing oscillatory movement that shall not be subject to the above-described disadvantages and limitations, but that, to the contrary, shall provide for ready adjustability, wide range of oscillation frequency, and simplicity and low cost.

A further object is to provide an improved oscillating apparatus that is particularly adapted for controlling the frequency sweeping or variation or other repetitive variations in electrical systems.

Still another object is to provide a novel oscillatory device of more general utility, also.

In summary, the invention preferably employs a magnetic stator provided with a pair of opposing alternating field-producing members that, when energized, tend to cause a magnetic armature or rotor to oscillate back and forth. Biasing means is applied to the armature to tend to hold the same against movement and to store energy as the field causes the armature to move, the biasing means releasing the stored energy to impart reverse-direction movement to the armature upon initiation of reversal of the alternating field. Load devices may be coupled to the oscillating armature, including a movable capacitor electrode for sweeping the frequency of an electrical oscillator, and a vibratory indicator for indicating the limits of oscillatory movement of the arma- Euro].1 Preferred constructional details are hereinafter set ort The invention will now be described in connection with the accompanying drawing, FIGURE 1 of which is a combined perspective and schematic circuit diagram of a preferred embodiment; and

FIGURE 2 is a fragmentary view of a modification.

In FIGURE 1, the novel oscillatory apparatus of the invention, operating in accordance with the method underlying the same, is shown applied to an electrical frequency-sweep system, though, as before explained, other types of load devices may also be employed. The frequency-sweep system may embody any conventional oscillator circuit 1 having a variable tuning element, such as a butterfly-type capacitor, comprising a fixed electrode 3 and a rotatably movable vane-type electrode 5. Other types of capacitors or other variable impedance elements may also, of course, be employed. The movement of the electrode 5 to different orientations relative to the electrode 3, will cause tuning of the oscillator circuit to different frequencies; so that back-and-forth mechanically oscillatory movement of the electrode 3, as between the dotted lines there-adjacent, will result in cyclical sweep variation of the electrical oscillation frequency of the oscillator circuit 1.

A magnetic armature 7, preferably, for economy purposes, a permanent magnet cylinder with diametric north-south pole orientation, shown vertical, is rotatably mounted within a magnetic stator assembly 9 having a first pair of preferably diametrically opposed magnetic legs 11 and 11, orthogonal to the pole orientation of the armature 7, and carrying respective windings 13 and 13 that may be energized from an alternating-current voltage source 15. The windings 13 and 13 are disposed to generate fields at 11 and 11' that reverse or alternate each half cycle of the frequency of the source 15. Thus, during one half cycle, the armature 7 will tend rotatably to move toward the leg 11, and, at the next half cycle, will tend to oscillate back in the opposite direction toward the leg 11'.

In actual practice, it has been found, however, that a resilient bearing and energy-storing mechanism is required to enable reliable, controlled and variable back-andforth oscillatory partial rotational movement of the armature 7 within sharply defined predetermined positional limits. In FIGURE 1, this resilient bearing and storage function is performed by a steady direct-current magnetic field produced between the vertically oriented stator legs 17 and 17, alined with,;but in pole opposition to the vertical armature pole orientation shown, by respective windings 19 and 19' energized from the source 21. This south-north biasing field will tend to oppose rotational movement of the north-south armature 7 clockwise or counterclockwise, storing energy as the alternating driving field at 13-13, of sufficient strength, forces such movement of the armature 7 in opposition to the biasing field; such that, upon initiation of reversal of the alternating driving field, a strong magnetic resilient-like counter force is exerted tending to spring the armature 7 back in the reverse direction. Under these circumstances, wide ranges of oscillatory frequencies for the armature 7 may be attained, ranging from a few cycles per second to thousands, and above. By mechanically axially coupling the armature 7 to the movable electrode 5, as by the rearwardly extending light shaft 2, the frequency of the Patented July 4, 1967 oscillator 1 will be swept back and forth at the rate of the mechanical oscillatory movement of the armature 7.

The limits or band of the swept frequency of the oscillator circuit 1 (or, more generically, the limits or amplitude of oscillatory back-and-forth rotational'movement of the armature 7 of this novel motor 7-9) may be directly synchronously indicated by axially coupling a vibratory pointer 4, as by the light forwardly extending shaft 6, to the armature 7. A blur of vibratory positions of the pointer 4, indicated by the dot-ted lines adjacent the pointer 4, will show the frequency sweep limits which may be read off the frequency scale 8. These limits may be varied by varying the field strength of the alternating magnetic field generated at 13, 13, as by varying the voltage applied thereto at the potentiometer P It has also been found that oscillatory limit variation may be achieved by varying the D-C field at 19, 19', as by the potentiometer P It has been found less desirable, however, to modify the resilient biasing-and-storage field, and more satisfactory to adjust the alternating-current field at P to different values above the fixed biasing field.

Alternatively, a mechanical spring may be employed instead of the spring-like biasing field, as at in FIGURE 2. The spring 10 is connected to the shaft 6 and serves the same function as the D-C field at 19 and 19'. It is preferable, for most sensitive operation, mechanically to tune the resonant frequency of the spring 10 to the frequency of the alternating-current of the driving source 15.

Facile change of the center frequency of the swept frequency band (or more generically, the initial or zero position of the electrode 5 or armature 7) may be effected by rotating the stator assembly 9, as by the knob 12, clockwise or counterclockwise relative to the fixed electrode 3.

As a practical example, apparatus of the type shown in FIGURE 1 has been satisfactorily operated with an oscillator 1 of from 460-1010 megacycles per second frequency band; an A-C source of 60 cycles (3600 back-andforth sweeps per minute); 117-vol-t windings .11-11; a voltage adjustment at P to produce from 0 to volts for energizing the windings 11-11', with angular oscillatory limits of from 0 to a full ninety degrees to cover the complete above-mentioned band; and a bias field at 19- 19 of about 30 volts, D-C.

Because of the balanced armature construction of the invention and the absence of off-center thrusts and other disadvantageous unbalancing features of present-day rotary-to-oscillatory converters and the like, before discussed, minimal vibration of the assembly is produced and the apparatus is not limited in its power, size or speed of operation, being useful for operation at from a few watts to thousands of horsepower.

Clearly, other armatures than a cylinder magnet may be employed as may more pairs of driving and/ or biasing windings, and other movement paths than rotational. Further modifications will also occur to those skilled in the art and all such are considered to fall within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. Oscillatory apparatus having, in combination, movable permanently magnetized armature means with opposite permanent magnet poles, magnetic stator means disposed to cooperate with the armature means for causing movement of the armature means and provided with a pair of opposite magnetic-field producing members, means for energizing the magnetic-field producing members at a predetermined frequency to generate a cyclically reversing field for tending to cause the armature means to oscillate back and forth, means for biasing the armature means againstmovement and storing energy as the generated field causes the armature means to move against the biasing, the biasing means releasing the stored energy to impart reverse-direction movement to the armature means upon the initiation of reversal of the genera-ted field, an electrical oscillation circuit having oscillation frequency varying means including a pair of relatively movable electrodes, one of which is coupled to said armature means to oscillate back and forth therewith, and means for adjusting the initial position of said one electrode relative to the other to change the center frequency of the frequency variation, said adjusting means comprising means for moving the said stator means relative to said other electrode.

2. Apparatus as claimed in claim 1 and in which indicator means is mechanically coupled to the armature means in order to indicate the limits of oscillatory movement thereof, thereby to indicate the limits of frequency variation of the said circuit.

3. An oscillating motor comprising a stator having a first pair of spaced oppositely disposed legs and a second pair of spaced oppositely disposed legs orthogonal to the first pair, means for applying a steady magnetic field to said first pair of legs to create a north pole at one leg thereof and a south pole at the other, a permanent magnet rotor disposed for oscillation between said legs and having opposite north and south poles adjacent to the south and north poles of said first pair of legs, respectively, when the rotor is at rest, and means for applying a cyclically reversing magnetic field to said second pair of legs to cause said rotor to oscillate.

4. The motor of claim 3, said rotor being substantially cylindrical with a substantially diametric pole orientation.

5. The motor of claim 3, further comprising means for varying the cyclically reversing magnetic field to vary the limits of oscillation of the rotor.

6. The motor of claim 3, further comprising means for varying the steady magnetic field to vary the limits of oscillation of the rotor.

References Cited UNITED STATES PATENTS 1,202,446 10/19'16 Speed 3l0-36 X 2,289,183 7/1942 Ehret et al 331-l78 X 2,635,155 4/19-53 Barr BIO-38 X 2,769,946 11/ 6 Brailsford 318-12-8 2,960,643 1l/1960 Boyd 310-38 X 3,040,223 6/ 1962 Buhrendorf 31036 X 3,214,662 10/1965 De Wolf 3311l6 X FOREIGN PATENTS 744,786 2/ 1956 Great Britain.

ROY LAKE, Primary Examiner.

J. B. MULLINS, Assistant Examiner. 

1. OSCILLATORY APPARATUS HAVING, IN COMBINATION, MOVABLE PERMANENTLY MAGNETIZED ARMATURE MEANS WITH OPPOSITE PERMANENT MAGNET POLES, MAGNETIC STATOR MEANS DISPOSED TO COOPERATE WITH THE ARMATURE MEANS FOR CAUSING MOVEMENT OF THE ARMATURE MEANS AND PROVIDED WITH A PAIR OF OPPOSITE MAGNETIC-FIELD PRODUCING MEMBERS, MEANS FOR ENERGIZING THE MAGNETIC-FIELD PRODUCING MEMBERS AT A PREDETERMINED FREQUENCY TO GENERATE A CYCLICALLY REVERSING FIELD FOR TENDING TO CAUSE THE ARMATURE MEANS TO OSCILLATE BACK AND FORTH, MEANS FOR BIASING THE ARMATURE MEANS AGAINST MOVEMENT AND STORING ENERGY AS THE GENERATED FIELD CAUSES THE ARMATURE MEANS TO MOVE AGAINST THE BIASING, THE BIASING MEANS RELEASING THE STORED ENERGY TO IMPACT REVERSE-DIRECTION MOVEMENT TO THE ARMATURE MEANS UPON THE INITIATION OF REVERSAL OF THE GENERATED FIELD, AN ELECTRICAL OSCILLATION CIRCUIT HAVING OSCILLATION FREQUENCY VARYING MEANS INCLUDING A PAIR OF RELATIVELY MOVABLE ELECTRODES, ONE OF WHICH IS COUPLED TO SAID ARMATURE MEANS TO OSCILLATE BACK AND FORTH THEREWITH, AND MEANS FOR ADJUSTING THE INITIAL POSITION OF SAID ONE ELECTRODE RELATIVE TO THE OTHER TO CHANGE THE CENTER FREQUENCY OF THE FREQUENCY VARIATION, SAID ADJUSTING MEANS COMPRISING MEANS FOR MOVING THE SAID STATOR MEANS RELATIVE TO SAID OTHER ELECTRODE. 